Minimally invasive or video assisted surgical procedures are being developed to reduce trauma, surgically induced complications, and costs associated with a lengthened hospital stay. One common, and costly operative procedure in the US is coronary artery bypass grafting (CABG), therefore, considerable attention has been given to establishing procedures for performing CABG surgery as a minimally invasive operation. Two basic approaches are currently being investigated by cardiac surgeons:
CABG (and other heart) operations on an arrested heart with percutaneous cardiopulmonary bypass (CPB); and PA1 CABG procedures on a beating heart without cardiopulmonary bypass.
There are certain advantages to the second approach in that CPB is known to be associated with some complications that can occur in open heart surgery. However, surgery on a beating heart is technically difficult, especially when performed through a small incision between ribs. Thus, there is a need to facilitate CABG surgery on a beating heart performed through an incision. A common CABG procedure is a graft between the left internal mammary artery (LIMA) and the left anterior descending (LAD) coronary artery. While several other coronary arteries may be treated by CABG, and other vessels can be grafted to the LAD, a LIMA-LAD graft will be discussed below as illustrative of the invention.
To access and work on the LAD while the heart is beating requires clamping or immobilizing at least a portion of the heart. Previously surgeons have used hand held surgical devices for limiting some motion of the heart. However, these devices are not particularly effective in limiting the motion of the heart and they require that an assistant place at least one hand near the surgical site. Other devices provide retractor assemblies for retracting tissue around a surgical opening to provide a sufficiently large access for surgery, and further provide mechanisms whereby retractor blades, used to pull back organs or tissue, or other surgical implements are attached to the retractor assembly. The retractor itself generally consists of a frame which fits or is assembled about a perimeter of the opening.
However, the implements of these assemblies do not have complete access to the surgical field. In other words, the mechanisms which attach the implements to the retractor assemblies allow only limited freedom of movement. Thus, if a surgeon uses such a configuration and adds further specialized surgical implements, the limited freedom of movement might complicate the surgery. For example, when a surgeon creates an incision for heart surgery and places a retractor, the heart is still covered with the pericardial membrane, an opaque tissue, and the surgeon can not clearly determine the location of the artery of interest at this point in the surgery. Thus, if the surgeon wants to attach a device to the retractor to locally limit the motion of the heart, the surgeon is required to estimate the location of the artery of interest and place the retractor and device accordingly.
Upon removing the opaque tissue and discovering the actual location of the cardiac artery, it may be necessary to reposition both the surgical implements and the retractor. To disassemble and re-configure a retractor and associated surgical implements takes time, and puts the patient at risk of complications.
Therefore, there is a need for a more versatile retractor assembly with attached surgical implements that have greater and more flexible access to the surgical field. There is also a need for surgical implements that are more effective in limiting the motion of the heart and do not require an assistant to place a hand near the surgical site.